<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 300px;
            height: 300px;
            border: 1px solid #ccc;
            margin: 50px auto;
            background: purple;
            display: none;
        }
    </style>
</head>
<body>
<input type="button" value="淡入" id="btn">
<input type="button" value="淡出" id="btn1">
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
</body>
</html>
    <script src="js/jquery-1.10.1.js"></script>
    <script>
        $(function () {
            $("#btn").click(function () {
                $(".box").fadeIn(5000,function () {
                    $(this).next().fadeIn(5000,arguments.callee);
                });
            })

            $("#btn1").click(function () {
                $(".box").fadeOut(3000,function () {
                    $(this).next().fadeOut(5000,arguments.callee);
                });
            })
        })
    </script>
